Trip-free mechanism for tank circuit breakers



Aug. l0 1926. l

w. o. cOA'rEs TRIP FREE MECHANISM FOR TANK CIRCUIT BREAKERS Filed Sept. 19, 1922 2 Sheets-Sheet 1 Fig.

INVETOR Will/@mA C Oates BYy AT'TORNEY Aug. l0 1926. 1,595,757

w. O. coATEs TRIP FREE MECHANISM FOR TANK CIRCUIT BREAKERS Filed Sept. 19, 1922 2 Sheets-Sheet 2 vnTNEssEs: INVENToR M6 E WiHiamAQoates l -Paienied Aug. io, 1926. i 1,595,757

UNITED STATESA PATENT OFFICE.

`WILLIAM A. CoaTEs, or CHARLTON-CUM-HARDY, ENeLANii, AssieNon To wasfriNe- House:A ELECTRIC a MANUFACTURING COMPANY, A ConroaArIoN or PENNSYL- vANu.

TRIP-FREE MECHANISM FOR TANK CIRCUIT BREAKERS. Application nl ed September 19, 1922, Serial Nb. 589,057, and in England September 29, 1921.

My invention relates Ito operating mechaswitch, the trip catch is located immediately 55 nisms for electric circuit interrupters, parabove'thel switch rod or element carrying ticularly to circuit interrupters having relathe brid e o r moving contacts so that, when tively movable contact members operating the catch 1s tripped, the switch is permitted in liquid baths. l to open independently of any movement of One ob]e ct ofmy inventioniis to provide the operating mechanism. i 60' a quick-acting circuit interrupter. The tripping catch comprises a releasable Another object of my` invention is to procouplin arran edisubstantially immediately vide a trip-free device which permits separaabove t e vertically moving switch rod or tion of the Contact members independently element and adapted directly to connect the of the link mechanism for eiiecting engageend of the latter to the operating mechanism nient thereof. y y to permit the switch to be closed and Ato be A further object of my invention is, to held in the closed position by means of a provide a circuit interrupter in which the retaining catch and adapted, when tripped,

15 separation of the contact members is not completely to disconnect the said rod or ele- `hinderedby the inertia of an attached train ment so that the switch is permitted imof mechanical links.4 mediatel to open and is not subject to any It is also an object of my invention to delay w ichmight be due to movement of provide a pair of relatively movable Contact the operating mechanism. Means are pro- 20 members adapted to take advantage of the vided for automatically tripping the retain--4 magnetic blow-out force exerted by the arcv 'ing catch after the switch has opened and 745I stream during the separation of such memfor reconnecting the switch rod to the operbers. ating mechanism by means of the aforesaid In large capacity oil or other liquid coup ing in readiness to permit the switch switches, the short-circuit currents are often to be closed.

suiciently heavy to set up strong magnetic Any suitable form of retaining catch may fieldsY having a repelling or deflecting action be employed and it is preferably applied to upon the switch contacts and throwing such a. part of the lswitch-operating mechanism considerable extra loads upon the operating which is substantially in the lane of the mechanism, las will cause the latter to demovement of the switch rod so t at the force fleet and permit'the. switch contacts to open required to retain the switch in the closed B5 v slightly before the automatic release of the position is not transmitted through the linkswitch has operated. work of the operating mechanism. The Switch operating mechanism of this charcatch advantageously comprises a toggle '85 acter is commonly provided with a retainstrut pivotally connected, at one end, to a 5 nism proper from the actuating member or described with reference to the accompanying catch adapted jto hold the switch with fixed partof the switch and, at the other the necessary pressure inthe closed position end, to the operating mechanism at .a point and with a second trip catch forming what on the latter which is ad]a cent to the reis generally known as a loose hand e deleasable coupling. On closing the-switch,

40 vice which is interposed between the switch the toggle strut is adapted to be carried over operating mechanism proper and the actuits dead center to engage a fixed stop.r ating member or handle. tie link is attached to the toggle strut and is This arrangement permits the switch t0 so disposed that, when the switch is tripped, be opened either, positivel by vmoving the the link is engaged by the switch rod during 5 actuating member or han le whereby only its opening movement and the toggle is the retaining Catch is released or by means broken, cansinor the operatin mechanism to of a. device adapted to release the trip catch collapse and fllow the switc rod. and subsequentl the retaining catch and In order that the nature of fthe invention thereby also re ease the operating mechamay be clearly understood, it will now handle, a spring being generally provided to in drawings., in which-- 105 assist or accelerate the opening movement. igure 1 isa front elevation, partly7 in According to the present invention, with' section, of the upper part of. a three-p ase aview to o taining a quick opening of the elgctric switch providedl with Ioperating mechanism in accordance with the invention;

Fig. 2 is a side elevation of the device shown in Fig. 1, looking in the direction of the arrow II (Fig. 1)

Fi 3 is a view similar to Fig. 2 but showing t e operating mechanism in another posinon;

Fig. 4 is a sect-ional view on the line IV-IV, Fig. 1, looking in the direction of the arrow, certain parts being omitted for the sake of clearness;

Fig. 5 is a view similar to the right-hand portion of Fig. 2, parts beingin section on the line V`V, Fig. 1;

Fig. 6 is a sectional view of a detail hereinafter explained; and

Fig. 7 is a view illustrating a modified form of the invention.

eferring now to Figs. 1 to 6 of the drawings, the rods 11, 12 and 13 which ac` tuate the moving Contact or bridge pieces of the respective phases are connected to al common cross-bar 14 which is constrained to move in a vertical direction by any suitable means. The cross-bar is rigidly attached to a frame 15 by two switch rods 16 and appropriate nuts 17, the upper part of the right-hand rod 16 and the end of the rame 15 being clearly shown in the detail view, Fig. 6. The frame 15 is of a troughlike or cradle form open at the top, as shown in Figs. 4 and 5, and rotatably supports two shafts 18, 19 mounted parallel to each other (see Figs. 4 and 5).

Substantially midway of the length of the shafts, triggers 20` 21 (see Fig. 4) are firmly secured to said shafts, respectively, the ends 22, 23 of the triggers being adapted, in one position of the parts, to engage rollers 24, 25 carried on a bell-crank lever 26 also pivoted to the frame 15, or a projection therefrom, by a pivot 27. The ends of the two triggers may be connected by a comparatively light spring 28 and, in the position shown in Fig. 4, prevent the shafts from rotating in the direction of the arrows when the switch is open.

At each end of each moved, as indicated Figs. 5 and 6), l 30 which, in the position of. the parts shown in Figs. 4, 5 and 6, are horizontal and rest on two stirrups 31 adapted to slide the frame 15, one of such orices being shown in Fig. 5. These stirrups are slightly less in width than the of the shafts 18 be clear from Fig. 5, and are means of rods 33 from the 34 which is journalled in the last member 35 of the link mechanism.

It will be seen that the cross-bar 14 from which the switch rods are suspended is shaft a part is reat 29 (see particularly so as to leave flat portions I supported by the rods 16 from the frame 15, the weight being ultimately borne by the shafts 18 and 19, the flat portions 30 of which rest on the tops of the stirrups 31. The reactions at these points, therefore, tend to rotate said shafts-in the direction of the arrows shown in Fig. 5, but this rotation in the position shown is prevented by the engagement of the ends of the triggers 22, 23 with the rollers 24, 25.

The operating linkw`or k for closing the switch is indicated generally by the numeral 36 and is pivoted at fixed points 37, 38 in the framework of the switch. The link mechanism is duplicated at each end of the rod 34, as shown in Fig. 1, and is so proportioned that the rod 34 is constrained to move in a straight vertical direction. Said linkwork may be operated to raise the stirrup 31 by pressure applied in an upward direction at the point 39 by any suitable mechanism (not shown) to cause the link 40 to rotate in the counter-clockwise direction around the pivot 37 and, in the raised position, a roller at the point 39 may be engaged by a retaining trigger 41 to hold said linkwork in this position. For the purpose of tripping the lever 26, a solenoid 42 having a movable core 43 is provided, the upward movement of which acts on a bellcrank lever 44 pivoted at a iXed point 45 to cause the end 46 of Said lever to strike the end 47 of the trip lever 26 and rotate it in the clockwise direction, thereby disengagingthe rollers 24, 25 from the triggers 22, 23.

The operation of the switch is as follows: assuming that the various parts occupy the positions shown in Figs. 1 to 5, in which positions the switch is closed, the cross-bars 14 being raised, if the solenoid 42 is energized, the movablefcore 43 is raised, thereby causing the release' of the triggers 22, 23 as above described. The upward pressure of the stirrups 31 on the horizontal surfaces 30 of the shafts 18 and 19 will rotate these shafts in opposite directions, as shown by the arrows in Figs. 4 and 5, and, when said surfaces 30 become nearly vertical, the frame 15 will be released and move downwards, thereby causing the crossbar 14 to descend and open the switch. During the descent of the rods 16, the projectionsy thereon strike the lever 41 and rotate said lever on its pivot in a clockwise direction, thereby releasing the link 40. This permits the linkwork 36 to collapse and take the position shown in Fig. 3. The trip lever 26, being no longer in engagement with the end of the bell-crank lever 46, will permit the triggers 20, 21 to return to the positions shown in Fig. 4 under the action of the spring 28, and the surfaces 30 will re-engage with the upper ends of the stirruns 31.

To close the switch, an upward pressure is applied the position shown in Fig. 2, and

the locking lever 41 will re-engage to hold' it in this position. The upward moyement of the rod 34 will move the stirrups 31 upwards and, lb reason of their engagement with the sha ts 18 and 19, will move the frame 15 upwards, thereby closing the switch.

In order to assist the switch in opening, a spring 50 may-be provided at a suitablel point, for example, between the cross-bar 14 and the framework ofthe switch, and a spring 50a maybe provided to rotate the lever 41 to its locking position, shown in Fig. 2.

t will be observed that the action of the trip lever 26, in opening, immediately effects the release of the coupling between the rods 16 which are attached 'to the cross-bar and the stirrups 31 which are attached to the rod and that this coupling is arranged immediately above said rods so that the switch is ermitted to open without any delay whic might be due to movement of the operating mechanism, namely, the linkwork 36. By this means, a greater operating speed is obtained Awhen the switch is tripped, as no portion of the mechanism, except the cross-bar and the switch brushes themselves, is moved, which is a most important advantage. l

Inl place of the retaining lever 41, any suitable form of catch or -retaining device lmay be employed. Preferablv, however, such catch is a plied to a part oi the switchoperating mec anism which is substantially in the p ane of the movement of the switch rod 16 so that the force required4 to 'retain the switch in the closed position is not transmitted throughithe linkwork of the operating mechanism.

Fig. 7 illustrates another form of my invention in which a lever 48, corresponding to the lever 41, is struck byA thel fall of member 15. Instead of collapsing the entire toggle mechanism, as is done in the modification shown in Figs. 2 and 3, ajoint is broken by `link 49 drawing links 51 and 52 out of alinement. The o eration of the remaining parts of the device is the same as in the first modification.

Itis to be understood that such variations may be made in the details and arrangement of parts of my invention as fall within the spirit and scope of the appended claims.

1. In a circuit interrupter, a releasing mechanism comprising rollers having a pair of parallel portions of their surface constituting planes, a movable Contact member held by said rollers,

and means for operating said rollers whereby said contact member is released 2. In a circuit interrupter, the combination with a movable contact member, a rod supporting said mechanism for moving in .a vertical direction,

ping coupling contact member, and a link said supporting rod of a releasable triplocated between tlie supporting rod and the operating linkwork substantially immediately above the vertically Vmoving supporting rod for permitting the switch to open independently of any movement of said operating ingdevice adapted to maintain ing linkwork sumes when ing linkwork In a link comprising a trigger mounted on each releasing said tions of said liiikwork, a retainthe operatin the position which it yasthe switch is closed, said retaining device l opening movement of and by rod and contact member to cause being tripped during the the supporting the operatto collapse when the switch mechanism, a tripping means pair `of horizontal rollers, a roller, mea-ns for triggers, semi-circular porrollers being cut awaynsupr porting members bearing'on the remaining portion of the rollers, whereby the rollers are adapted to -roll ing members upon gers.

4. In a link liberating the .free from said support-- the release of said trigmecha/nism, the combination a member supported a releasing means for supported member independently of the linkwork, and means for collapsing said` linkwork during the fall and by the force of said supported member.

5. In a releasing mechanism, a pair of rotatable parallel members, supporting means bearing on said rotatable members, semi-circular portions of material being cut away from said rotatable members at the bearing points to form flat faces, whereby said ro- -tatable members may roll from the supporting means and fall, the remaining between tatable members supporting means the fiat faces of said roduring the downward movement of the rotatable members.`

In testimony whereof, I have hereunto subscribed my name tember, 1922.

this first day of Sep- WILLIAM A. CATES. 

